Spark Plug Heat ranges, what gains have you made?

[Stan Weiss]

When you add wrist pin offset a number of thinks happen. The piston and the crank rod journal are not ATDC and BBDC at the same time. Now based on which way you have the offset decides if piston TDC is before or after crank rod journal TDC. Another thing that happens is all 4 cycle are not long 90 degrees each. 2 become less and 2 become more. Again which 2 do what is based on where the offset was placed.The is also a very very small change in stroke and displacement. (For inline engines where you can move / offset the crank center line these can be larger).


Stan

[Jeff Stout]

Originally Posted by Stan Weiss

When you add wrist pin offset a number of thinks happen. The piston and the crank rod journal are not ATDC and BBDC at the same time. Now based on which way you have the offset decides if piston TDC is before or after crank rod journal TDC. Another thing that happens is all 4 cycle are not long 90 degrees each. 2 become less and 2 become more. Again which 2 do what is based on where the offset was placed.The is also a very very small change in stroke and displacement. (For inline engines where you can move / offset the crank center line these can be larger).


Stan

Did not think of this. Could you run just 4 pistons with offset? Don't know if it is worth anything as I understood using offset helps with side thrust on bore.

[Bruce Fulper]

Originally Posted by MoJo Risen

Enhanced tune for my vehicle is, running ignition Timing right on the edge of pre ignition.

"on the edge of pre ignition" ?? Detonation and pre ignition are two very different things. Pretty sure you meant detonation.

[MoJo Risen]

Originally Posted by Bruce Fulper

"on the edge of pre ignition" ?? Detonation and pre ignition are two very different things. Pretty sure you meant detonation.

No Bruce, it's a TURBO car, high Combustion pressure.

Turbo cars have a tendency to have low speed Pre ignition with much higher Combustion pressure....

But, I am here to gather ideas and have looked further into detonation.
I can see how they can be confused with one another.
Thank you for the response.

I do look forward to the NGK heat range 9 plug to test.